The present invention relates to a phono pick-up cartridge for a record player. More specifically, the present invention relates to a magnetic type phone pick-up cartridge.
Prior art magnetic phono pick-up cartridges have been commercially available for a number of years and have been used in applications requiring a broad frequency response. However, the prior art magnetic phono pick-up cartridges suffered from a number of defects. In these cartridges, both the holder for the cantilever holding the stylus and the vibrating body attached thereto had to be magnetic. A large magnetic yoke, which most commonly included only front and center members, had to be made very heavy as did the holder and vibrating body. Also, most generally, air core coils could not be used, and each coil had to be provided with a core of magnetic material.
Because of this, the compliance of the vibrating system of the cartridge was rather low and a high stylus pressure was needed. A rubber damper attached to the cantilever had to be made from a relatively hard rubber in order to firmly mount the stylus due to the high stylus pressure. As a result, the magnetic efficiency of the cartridge was quite low typically only several percent. Yet further, no adjustment could be made to align the coils with the magnetic circuit. This led to an unbalance in some situations in the output signals from the left and right channels.
Accordingly, it is an object of the invention to provide a magnetic phono pick-up cartridge in which all of these defects are eliminated.
More specifically, an object of the present invention is to provide such a phono pick-up cartridge in which the weight of the components used therein is relatively small, and in which a high stylus pressure need not be used.
Still further, it is an object of the present invention to provide such a cartridge in which a relatively soft rubber damper can be used to improve the frequency response thereof, and to provide such a cartridge in which the magnetic efficiency is relatively high.